Tom Brown
'Smilin' Jack' Martin
Marjorie Lord
Janet Thompson
Rose Hobart
Trudy Muller, aka Fraulein von Teufel
Edgar Barrier
Tommy Thompson
Cyril Delevanti
Mah Ling / Han Po, his double
Turhan Bey
Kageyama [Chs. 1-5, 12-13]
Sidney Toler
General Kai Ling [Chs. 1-5, 13]
Jay Novello
Kushimi, infiltrator [Chs. 1-3, 12-13]
Rico De Montez
Henchman Hito [Chs 1, 4, 12-13]
Nigel De Brulier
The Lo-San [Chs. 2-3, 12-13]
Edward Keane
Hon. George Hill [Chs. 8-12]
William Forrest
Secretary of Internal Affairs [Chs. 8-12]
Jack Gardner
Captain Yoshido [Chs. 1-3]
Terry Grey
Shuma, pilot [Chs. 1-3]
Stanley Blystone
Capt. Hardigan [Chs. 5-6]
Herbert Heyes
Sir Cedric [Chs. 5-7]
James Craven
Commissioner Robert George Hardy [Chs. 5-7]
Alex Havier
Sanson, phoney waiter [Chs. 6-7]